January 31, 2011

Babies Recognize Social Dominance

(Ivanhoe Newswire) -- Your baby may be trying to figure out who's the boss. A new study reveals infants understand social dominance and use relative size to predict who will prevail when two individuals have conflicting goals.

Lead author Lotte Thomsen, of Harvard and the University of Copenhagen, and colleagues at UCLA studied the reactions of infants ranging from 8 to 16 months of age as they watched videos of interactions between cartoon characters of different sizes.

"Since preverbal infants can't be interviewed, their experiences and expectations must be assessed by their behavior," Thomsen was quoted as saying. "Infants tend to watch longer when something surprises them. So we can test hypotheses about what they expect by measuring how long they look at scenarios that either violate or confirm their expectations."

The investigators showed infants videos where a large and small block with eyes and a mouth bounced across a stage in opposite directions. Next, the infants watched the two blocks meet in the middle, impeding one another's progress. They then saw either the large or small block bow and step aside, deferring to the other.

"As predicted by our theory, the infants watched much longer when a large agent yielded to a smaller one," Thomsen said. On average, the babies watched this unexpected outcome for 20 seconds compared to just 12 seconds when a smaller character made way for a larger one.

"Traditional kings and chieftains sit on large, elevated thrones and wear elaborate crowns or robes that make them look bigger than they really are, and subordinates often bow or kneel to show respect to superior humans and gods," Thomsen said. "Many animals, like birds and cats, will puff themselves up to look physically larger to an adversary, and prostrate themselves to demonstrate submission, like dogs do. Our work suggests that even with limited socialization, preverbal human infants may understand such displays."

In a follow-up experiment, the researchers found 8-month-old infants couldn't grasp the significance of the larger block deferring to the smaller one. However, infants aged 10 to 16 months were consistently surprised at depictions of a larger individual yielding to a smaller one. Researchers say this suggests that conceptual understanding develops between 8 and 10 months.

SOURCE: Science, Jan. 2011